The consumption of polyunsaturated fatty acids has changed, and the prevalence of adiposity has increased over the past 30 y. A decrease of n-3 polyunsaturated fatty acid content in breast milk has been suggested to be a contributing factor. The objective of this study was to investigate the relationship between docosahexaenoic acid (DHA) content and n-6/n-3 polyunsaturated fatty acid ratio in breast milk, body composition, and timing of adiposity rebound in children.